Composting of coffee husk waste as circular economy practice in local coffee bean production

Purpose: This study aims to investigate the composting process and characteristic of coffee husk waste to transform it into organic fertilizer, addressing the urgent need for repurposing coffee husk waste and promoting sustainable agricultural practices. Method: The composting process involved collecting coffee husk waste from the UD Cipta Lestari coffee factory, enriching it with goat faeces, and supplementing it with dolomite and an EM4 bio activator. We monitored the temperature and pH levels throughout the composting process and characterized the compost yield for key physicochemical parameters with duplicate sampling at the end of the composting process (76 and 67 days). Result: The composting process yielded promising results, with notable variations observed in pH, organic matter content, total nitrogen, available phosphorus, available potassium, moisture content, and C/N ratio across the four samples. KK B2 demonstrated particularly favourable results across multiple parameters, indicating its potential as a high-quality organic fertilizer. Conclusion: While all samples met the requirements for composting and soil amendment, KK B2 exhibited superior characteristics, including higher levels of organic carbon, total nitrogen, and available potassium. However, selecting the most suitable compost for specific agricultural needs should consider a holistic evaluation of all parameters and local soil conditions. Overall, the study underscores the potential of composting as a sustainable solution for repurposing coffee husk waste and promoting soil health in agricultural systems. Further optimization of composting conditions and management practices could enhance the quality and consistency of the final compost yield, contributing to sustainable waste management and agricultural productivity in coffee-producing regions. Research Highlights • This study aims to investigate the composting process and characteristics of coffee husk waste to transform it into organic fertilizer • The composting process involved collecting coffee husk waste from the UD Cipta Lestari coffee factory, enriching it with goat feces, and supplementing it with dolomite and an EM4 bio activator. • The composting process yielded promising results with notable variations observed in pH, organic matter content, total nitrogen, available phosphorus, available potassium, moisture content, and C/N ratio across the four samples. • KK B2 demonstrated particularly favorable results across multiple parameters, indicating its potential as a high-quality organic fertilizer. • The study underscores the potential of composting as a sustainable solution for repurposing coffee husk waste and promoting soil health in agricultural systems.